1. Field of the Disclosure
The present disclosure relates to a light receiving device capable of receiving light of a specific wavelength region.
2. Description of the Related Art
A light sensor module is disclosed in Japanese Unexamined Patent Application Publication No. 2013-79852. A light receiving device employed in this light sensor module includes a light receiving element that generates current according to the quantity of received light, and a wavelength selection filter member that is disposed on the light incident side of the light receiving element. This wavelength selection filter member has a constitution in which wavelength selection filter films are laminated on an optical substrate, and transmits light of a desired wavelength incident on the incident surface.
However, since the light receiving device described in Japanese Unexamined Patent Application Publication No. 2013-79852 has a constitution in which wavelength selection filter films are laminated on one surface of an optical substrate, the setting of a transmittance wavelength band is limited. To solve this problem, an optical substrate on which wavelength selection filter films are laminated can be added. However, in this case, since the number of optical substrates increases, the thickness of the whole light receiving device increases, and the light sensor module may increase in size.